import { NativeEventEmitter, type EmitterSubscription } from 'react-native';
// @ts-ignore
import EventEmitter from 'react-native/Libraries/vendor/emitter/EventEmitter';
import LiveKitModule from '../LKNativeModule';

// This emitter is going to be used to listen to all the native events (once) and then
// re-emit them on a JS-only emitter.
const nativeEmitter = new NativeEventEmitter(LiveKitModule);

const NATIVE_EVENTS = [
  'LK_VOLUME_PROCESSED',
  'LK_MULTIBAND_PROCESSED',
  'LK_AUDIO_DATA',
];

const eventEmitter = new EventEmitter();

export function setupNativeEvents() {
  for (const eventName of NATIVE_EVENTS) {
    nativeEmitter.addListener(eventName, (...args) => {
      eventEmitter.emit(eventName, ...args);
    });
  }
}

type EventHandler = (event: unknown) => void;
type Listener = unknown;

const _subscriptions: Map<Listener, EmitterSubscription[]> = new Map();

export function addListener(
  listener: Listener,
  eventName: string,
  eventHandler: EventHandler
): void {
  if (!NATIVE_EVENTS.includes(eventName)) {
    throw new Error(`Invalid event: ${eventName}`);
  }

  if (!_subscriptions.has(listener)) {
    _subscriptions.set(listener, []);
  }

  _subscriptions
    .get(listener)
    ?.push(eventEmitter.addListener(eventName, eventHandler));
}

export function removeListener(listener: Listener): void {
  _subscriptions.get(listener)?.forEach((sub) => {
    sub.remove();
  });

  _subscriptions.delete(listener);
}